This invention relates to a refrigeration cycle apparatus, and more particularly to a refrigeration cycle apparatus having a heat accumulating unit for accumulating excess heat during normal heating operation and for releasing the heat to a refrigerant path when necessary.
As is well known, a refrigeration cycle apparatus comprises a compressor, condenser, expansion valve, evaporator, etc. The apparatus can be used as either a cooler or a heater, by changing the direction in which the refrigerant flows, and is widely used.
When the apparatus is used as a heater, it requires a considerably long time until it starts generating warm air. This is because the components, such as the compressor and condenser, are cold when the apparatus is turned on. The refrigerant is also cold at this time. Naturally, the user would prefer to have the apparatus which blows out warm air as soon as it is turned on. To meet this demand, conventional apparatuses have an electric heater provided on the case of the compressor to heat the compressor. The heater is turned on when the heating operation is started. The heater therefore accelerates the heating of the refrigerant, and enables the apparatus to deliver warm air sooner. However, since the heater consumes electric power, the apparatus is disadvantageous in view of energy costs.
Recently it has been proposed that the excess heat generated during the heating operation be stored in heat-accumulating material, and later be released to heat the refrigerant whenever the apparatus is started up. This method can indeed enable the apparatus to provide warm air soon after it has been turned on, but has the following drawbacks.
It is necessary to prevent the heat from escaping the heat-accumulating material over a long period of time. To satisfy this requirement, the container for the material must be sufficiently insulated to prevent the heat from radiating outside. The use of a sufficiently insulated container increases the cost and the size of the apparatus. Due to these drawbacks, the apparatus using the heat-accumulating material is not desirable for practical use.